The present invention relates in general to power transfer assemblies. More particularly, the present invention relates to a power transfer assembly equipped with a coplanar gear assembly.
Due to increasing consumer demand for front wheel drive vehicles with more powerful yet fuel-efficient drivetrains, the engine and transaxle must be efficiently packaged to take advantage of all available space within the engine compartment. Concomitantly, most modern transaxles must be capable of providing at least forward five speed ratios. As such, minimizing the overall size of the transaxle is of critical importance to the transmission designer. To meet these requirements, various xe2x80x9cthree-shaftxe2x80x9d type transaxles have been developed. For example, U.S. Pat. No. 4,738,150 discloses a five-speed manual transaxle having an input shaft and a pair of countershafts both of which drive a differential which, in turn, drives a pair of axle half-shafts. Gearsets on both counter-shafts can be selectively engaged to deliver power from the input shaft to the axle half-shafts. Furthermore, U.S. Pat. Nos. 5,385,065 and 5,495,775 disclose five-speed transaxles having a synchronized reverse gear arrangement.
Accordingly, while such conventional manual transaxle designs attempt to address the packaging requirements mentioned above, a need still exists for development of more compact and robust manual transaxles that can meet the demands of modern front wheel drive vehicular applications.
The primary object of the present invention is to provide a multi-speed manual transaxle that meets the above-noted needs and improves upon conventional designs.
Accordingly, the present invention is directed to a differential gear mechanism which can be used in a transaxle and is driven by a pinion gear and operable to permit relative rotation between a first axle shaft and a second axle shaft, the differential gear mechanism including a sun gear adapted to be splined for rotation with the first axle shaft. An annulus/ring gear including external teeth is adapted to meshingly engage teeth of the pinion gear. A cluster gear including external teeth is in meshing engagement with internal teeth of the annulus/ring gear and has internal teeth in meshing engagement with said sun gear. A carrier supports the cluster gear and is adapted to be splined for rotation with the second axle shaft.
The present invention is also directed to a transmission device comprising an input shaft; a coplanar gear arrangement having a plurality of components including a sun gear in meshing engagement with a cluster gear, said cluster gear being supported by a carrier and including internal teeth in engagement with said sun gear, and an annulus gear including internal teeth in engagement with external teeth of said cluster gear, said input shaft being in driving engagement with one of said components of said coplanar gear arrangement; an output shaft in driving engagement with a second one of said components of said coplanar gear arrangement; and a coupling mechanism operable to selectively engage a third of said components of said coplanar gear arrangement to one of said input shaft and a housing of said transmission.
Areas of applicability of the present invention will become apparent form the detailed description provided herein. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this description.